Wind turbine

ABSTRACT

A wind turbine assembly including a rotor body having mounted thereon a plurality of rotor blades. Each of the rotor blades may be joined at an inner extremity to a blade stem projection extending interiorly into the rotor body and secured to the rotor body by a torsional-spaced and axial-shock damping connection. The blade stem projection may also be secured within the rotor body in a manner allowing limited rotation of the blade stem projection relative to the rotor body, corresponding to a selective range of pitch of the associated rotor blade, with a system for rotating a blade stem projections of each of the rotor blades by corresponding degrees of rotation to provide a predetermined pitch of the rotor blades. Also disclosed are pitch-damping tower designs, and an integrated design wherein the tower is pitch- and yaw-damped.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates generally to wind turbine apparatus, and morespecifically to a wind turbine rotor assembly of low weight and compactcharacter, a turbine mounting system of low weight and flexiblecharacter with respect to its ability to translate in response tochanges in wind direction, and a pivoting support tower.

2. Description of the Prior Art

A variety of wind turbine systems have been proposed and/or employed inthe art.

These systems, while representing a wide variety of shapes, structures,and features, are generally classifiable by wind turbine axis direction,yaw character (free yaw, damped, or driven yaw), and wind turbine bladepitch (fixed pitch or variable pitch).

Horizontal axis wind turbines are characterized by an axis of rotationwhich is parallel to the ground. Vertical axis wind turbines arecharacterized by an axis of rotation which is perpendicular to theground. Horizontal axis wind turbines may deploy the rotor either upwindor downwind of the associated supporting tower. Horizontal axis windturbines typically feature one of three design modalities to adjust theposition of the rotor to the changing direction of the wind. Free yawwind turbines rotate freely on the supporting tower in response to winddirection, driven yaw wind turbines incorporate motors to rotate theturbine in response to changes in wind direction, so that the turbineactively tracks the changing direction of the wind. Damped yaw windturbines include damping device(s) which decelerate the otherwiseuncontrolled rotation of the turbine as the wind changes.

Variable pitch wind turbines include mechanisms for the adjustment ofthe pitch of the rotor blades with relation to the wind direction formaximum efficiency at a variety of wind speeds. Fixed pitch windturbines feature stationary rotor blades which have a constant pitch inrelation to the wind direction.

Wind turbine apparatuses also differ in rotor diameter and rated poweroutput. Single generator and multiple generator configurations areknown, and a wide range of power outputs are obtainable from windturbine apparatuses which have been commercialized to date.

Wind turbine apparatuses may be mounted for operation on a wide varietyof supports and towers, including self-supporting tubular towers,self-supporting lattice towers, or guyed tubular towers.

In addition to the above-described variant types of wind turbines, suchturbines may feature a wide variety of ancillary structural andoperation features. For example, a nacelle may be incorporatedsurrounding the rotor. Blade tip brakes may be incorporated to preventdamage caused by excessive rotational speeds at high wind velocities.

Examples of wind turbine apparatus which are commercially availableand/o in actual use include wind turbine apparatus of the followingmanufacturers: Holec/Polenko, (Netherlands) (upwind, fixed pitch, dualyaw rotors, self-supporting tubular tower); Holec/Windmatic (Denmark)(upwind, fixed pitch, dual yaw rotors, self-supporting lattice tower);Howden Windparks, Inc. (Scotland) (upwind, steel tubular tower withconical base); Micon (Denmark) (upwind, fixed pitch, self-supportingsteel tubular tower with inside ladder to nacelle); Nordtank (Denmark)(upwind, fixed pitch, steel tubular tower); Vestas (Denmark) (upwind,lattice tower); HMZ-Windmaster (Belgium) (upwind, hydraulically pitchedblades, tubular tower with inside ladder to nacelle); Dangren VindKraft/Bonus (Denmark) (upwind, fixed pitch, self-supporting steeltubular tower); FloWind Corp. (vertical axis); Enertech (downwind, freeyaw, blade tip brakes, self-supporting tower); Fayette ManufacturingCorp. (downwind, blade tip brakes, guyed pipe tower); U.S. Windpower,Inc. (downwind, free yaw, variable pitch blades, remote computer controltripod tower); Danish Wind Technology (Denmark) (downwind, free yaw withhydraulic damping, variable pitch, computer control, steel tubular towerwith inside ladder to nacelle); Energy Sciences, Inc. (downwind, bladetip brakes, free yaw, tilt-down lattice tower); Wind Power Systems(downwind, tilt- C down lattice tower, no nacelle); Danwin (Denmark)(upwind, tubular tower); BSW/Wagner (Germany) (upwind, fixed pitch,driven yaw, lattice tower); Alternegy/Aerotech (Denmark) (upwind,tubular tower with inside ladder to nacelle); W.E.G. (England) (upwind,tubular tower, variable pitch); and Windworld (Denmark) (upwind, fixedpitch, tubular tower).

Despite the wide variety of wind turbine systems which have evolved inthe art to date, as exemplified by the above-discussed designs, there isa continuing need for an improved wind turbine apparatus of low weightand compact character, which is structurally and operationally adaptedto perform in a wide variety of wind conditions, without adverse affecton the structural integrity and operability of the wind turbine system.Even in areas where the average wind speed is relatively constant on aseasonal or even annual basis, there nonetheless exist substantialvariations in wind direction and intensity.

Such shifting wind conditions even in computer-controlled yaw-driventurbine systems, entail substantial "shock" forces--tensional,compressive, and torsional forces--on the rotor blades, carbon body andinternal components, as well as the tower. Such shock forces, if notsatisfactorily damped or otherwise attenuated, can severely shorten theoperating life of the turbine assembly, and occasion damage to theturbine blades and components, thereby rendering the turbine apparatusdeficient or even useless for its intended purpose.

In addition, the art is continually seeking reduced weight and morecompact wind turbine structures, to render wind turbine systems moreeconomic in character and competitive as alternative energy systemsrelative to conventional coal-fired generating plants, nuclear powerfacilities, and hydroelectric systems.

Accordingly it is an object of the present invention to provide animproved wind turbine assembly of low weight and compact character.

It is another object of the present invention to provide a wind turbineassembly which is of low weight and flexible character with respect tothe ability of the wind turbine to translate in response to changes inwind direction.

It is a still further object of the present invention to provide animproved wind turbine assembly which features adjustable pitch rotorblades which are associated with independent suspension means, wherebymechanical and hydraulic shocks resulting from changes in wind directionand intensity are efficiently damped to minimize friction, wear, anddamage to the wind turbine assembly.

It is still another object of the present invention to provide a windturbine assembly mounting arrangement, by means of which the nacelle ofthe turbine assembly is secured to a supporting tower by coupling meanswhich provide highly efficient pitch and yaw damping of the turbine.

Other objects and advantages of the present invention will be more fullyapparent from the ensuing disclosure and appended claims.

SUMMARY OF THE INVENTION

The present invention relates to an improved wind turbine assembly,including improvements in the rotor body subassembly and means andmethod of securing rotor blades thereto, as well as improvements in windturbine towers, and arrangements for securing wind turbines tosupporting towers.

In one aspect, the invention relates to a wind turbine assemblyincluding a rotor body having mounted thereon a plurality of rotorblades, wherein each of the rotor blades is joined at an inner extremitythereof to a blade stem projection extending interiorly into the rotorbody and secured therewith to the rotor body by torsional- andaxial-shock damping connection means. Such shock damping connectionmeans may suitably employ any of a wide variety of means, such assprings, shock absorbers, and other biasing elements. Preferably each ofthe rotor blades is secured to the rotor body by independent dampingconnection means, to provide independent suspension to each of the rotorblades.

In another aspect, the present invention relates to a wind turbineassembly including a rotor body having mounted thereon a plurality ofrotor blades, wherein each of the rotor blades is joined at an innerextremity thereof to a blade stem projection extending interiorly intothe rotor body and secured therewithin to the rotor body in a mannerallowing limited rotation of the blade stem projection relative to therotor body, such limited rotation corresponding to a selected range ofpitch of the associated rotor blade, and means for selectively rotatingthe blade stem projections of each of the rotor blades by correspondingdegrees of rotation to provide predetermined pitch of the rotor blades.

The means for selectively rotating the blade stem projections of each ofthe rotor blades may suitably comprise:

(a) a control rod mounted coaxially within the rotor body with respectto the axis of rotation of the rotor body;

(b) means coupling the blade stem projection with a first end of thecontrol rod such that axial translation of the control rod in a firstdirection tensionally exerts a rotational force on the blade stemprojection in a first rotational direction and axial translation of thecontrol rod in an opposite second direction detensionally exerts arotational force on the blade stem in a second rotational directionopposite the first rotational direction; and

(c) means for selectively axially translating the control rod in aselected one of the first and second directions.

The coupling means (b) in the above-described assembly may suitablycomprise a cable and pulley arrangement, preferably one which includes afluid-damped shock absorber coupled to the cable.

The selected axial translation means (c) may comprise a piston joined toa second of the control rod and mounted in a hydraulic cylinder, withmeans for selectively introducing hydraulic fluid into the cylinder toeffect axial translation of the control rod in a selected one of thefirst and second directions.

In a further aspect, the present invention relates to a wind turbineassembly including a rotor body having mounted thereon a plurality ofrotor blades, a nacelle to which the rotor body is coupled for rotationwith respect to the nacelle; and a tower having an upper portion towhich the nacelle is secured by coupling means, and a lower portionpositionable on a support body, e.g., the ground. The coupling meanscomprise:

a swivel mounted member interconnecting the nacelle and the upperportion of the tower to permit rotation of the nacelle and rotor bodyrelative to the tower;

a first damping member interconnecting the nacelle and the upper portionof the tower, for pitch damping of the nacelle;

a second damping member interconnecting the swivel mounting member and afirst side of the tower upper portion, for damping yaw of the nacelle ina first yaw direction; and

a third damping member interconnecting the swivel mounting member and asecond side of the tower upper portion, for damping yaw of the nacellein a second yaw direction opposite to the first yaw direction.

The first, second, and third damping members of the system described inthe preceding paragraph may be independently selected from the groupconsisting of spring biasing elements, tensionally flexible guyingcables, and fluid-damped shock absorbers.

In still another aspect, the invention relates to a wind turbineassembly comprising a rotor body having a primary drive ring or sun gearattached thereto and engageable with a reduction gear which in turn isconnected to power generator unit(s), whereby the reduction gear isdriven by the primary drive ring gear for generation of power by thegenerator unit. The reduction gear may be mounted on a powertransmission shaft joined to the power generating unit, wherein thetransmission shaft has associated therewith breaking and/ordisengagement means to accommodate wind "cut in" and "cut out"conditions. The ring or sun gear may also be associated with a pluralityof reduction gears, each of which is coupled to an appertaining powergenerating unit, whereby the wind turbine assembly comprises a pluralityof such units.

The tower employed with the wind turbine assembly of the presentinvention may be configured in a wide variety of forms. In one aspect,the tower may be of a pivoting booming tower configuration, capable of a360° damped tower yaw. Such tower may incorporate a redundant limitedyaw damping system at the upper extremity of the tower. By limited yawdamping is meant a free yaw for a portion of the circle of rotation,e.g., 270 , with the yaw outside of such free yaw band of the rotationalcircle being damped by suitable damping means such as shock absorbers,coil springs, or similar means.

The wind turbine assembly of the present invention may utilize anysuitable number of blades, preferably from two to six blades.

Other aspects and features of the present invention will be more fullyapparent from the ensuing disclosure and appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevation view of a wind turbine assembly according toone embodiment of the present invention, comprising a downwind rotordesign.

FIG. 2 is a front elevation view of the wind turbine assembly of FIG. 1,viewed toward the downwind direction.

FIG. 3 is a side elevation view of a portion of the wind turbineassembly of FIGS. 1 and 2, showing the details of the couplingarrangement by means of which the nacelle of the turbine is secured toan upper portion of the tower.

FIG. 4 is a sectional plan view of the rotor body and associated turbinehousing portion illustrating the internal structure thereof, and theindependent suspension of the rotor blade elements relative to the rotorbody.

FIG. 5 is a plan view, in partial second, showing the internal structureof a turbine and independent suspension and variable pitch control ofthe associated rotor blades, together with the power generator unit inthe upwind portion of the turbine.

FIG. 6 is a front elevation view, toward the downwind direction, of awind turbine assembly according to another embodiment of the invention.

FIG. 7 is a side elevation view of the FIG. 6 wind turbine assembly.

FIG. 8 is a side elevation view of a portion of the wind turbineassembly of FIGS. 6 and 7, showing the details of the mounting of theturbine on a tubular tower of a self-guying character.

FIG. 9 is a front elevation view, looking toward the downwind direction,of a portion of the wind turbine assembly of FIGS. 6-8.

FIG. 10 is a schematic representation of a portion of a turbine bodyshowing a primary drive gear and its relationship to secondary gears, asarranged for generating power from four (or alternatively, eight) powergenerators disposed within the nacelle.

FIG. 11 is a schematic representation of a portion of the turbinecorresponding to FIG. 10 but axially displaced therefrom, and showingthe gearing associated with the power generators for achieving multiplecounter rotation operation with power output from all four (oralternatively, eight) generator units.

FIG. 12 is a schematic representation of a gearing arrangement forside-by-side counter-rotating generators in a wind turbine assembly.

FIG. 13 is a schematic representation of another gearing arrangementfeaturing equal-sized gears coupled with corresponding generator units.

FIG. 14 is a schematic representation of a gearing arrangement for awind turbine assembly, wherein counter-rotation of the generators iseffected by direct 90° axle linkage forwardly of the generator units.

FIG. 15 is a schematic representation of four generator units in aturbine body.

DETAILED DESCRIPTION OF THE INVENTION, AND PREFERRED EMBODIMENTS THEREOF

Referring now to the drawings, FIG. 1 shows a side elevation, and FIG. 2a corresponding front elevation view (looking toward the downwinddirection) of a wind turbine assembly 100 according to one embodiment ofthe present invention.

As shown in FIG. 1, the wind direction is indicated by arrow W.

The wind turbine assembly 100 shown in these drawings comprises a windturbine 101 mounted on a tubular support tower 114.

The turbine 101 comprises a rotor body 102 having mounted thereon aplurality of rotor blades 104, 106, and 108. The rotor body 101 isrotatably mounted on and connected to the nacelle 110, which in turn isjoined to an upper portion of tower 114 by coupling arrangement 112.

The tower 114 is a tubular support tower, comprising an upwind sparmember 116 and a downwind spar member 118 in spaced-apart relationshipto one another, as shown, and interconnected by a lattice-work structureof diagonal bracing members 120 and horizontal bracing members 122. Atthe lower portion of the tower, the spar members 116 and 118 are joinedto tubular member 124 and flange member 126, respectively. Tubularmember 124 is telescopingly mounted on shaft 128 extending throughfooting member 130 disposed at ground level G, as shown. By thisarrangement, the tower 114 is able to freely rotate about shaft 128, asdamped by yaw damping means of the coupling arrangement 112, ashereinafter more fully described.

The footing member 130 may be of concrete or other suitable structuralmaterial, of a sufficient size, weight, and stability to anchor thetower structure, and for this purpose, shaft 128 may extend downwardlyinto the ground for a suitable distance to impart structural stabilityand rigidity to the tower 114.

The tower 114 itself may be formed of any suitable material ofconstruction, preferably high strength metal or other materials such ashigh-strength engineering composites, etc.

Correspondingly, the rotor body 102, rotor blades 104, 106, and 108, andnacelle 110 may be constructed of any suitable materials, includingmetal, engineering plastics, composites, structural ceramics, and thelike.

Referring now to FIG. 3, there is shown a portion of the wind turbineassembly of FIGS. 1 and 2, showing the details of construction of thecoupling arrangement 112, by means of which the turbine 101 is securedto an upper portion of tower 114.

As illustrated, the rotor body 102 of turbine 101 has mounted thereonrotor blades 104 and 106, and the rotor body 102 is coupled to nacelle110, such that the rotor body 102 is freely rotatable against thestationary nacelle 110. The nacelle 110, as shown more fullyhereinafter, contains power generator units, and associated powertransmission, gearing, and control means necessary for proper operationof the turbine. The nacelle thus defines a turbine body portion whichremains stationary and which must accommodate the movement, vibration,shocks, and forces which arise in connection with the operation of theturbine 101, in a manner ensuring structural integrity of the overallassembly and reliable operation in terms of continuity of operation andminimization of down-time.

The nacelle 110 is mounted on the tower 114 by means of Y-shaped yokemember 140, the upper legs 144 of which are joined to the nacelle 110 atopposite sides thereof, by means of fasteners 146, e.g, mechanicalfastening means. The lower stem 142 of yoke member 140 is telescopicallypositioned in cylindrical member 138 which is in turn associated with aflange cap 136 at the upper end of the tower and joined to spar members116 and 118 and to support brace 132. The spar members 116 and 118 are,as previously described, in space-apart relationship to one another, andare braced with a lattice-work comprising diagonal brace members 120 andhorizontal brace members 122.

At its lower extremity, the stem 142 of yoke member 140 is joined to anoarlock connector 152, to which in turn is joined a pitch-damping shockabsorber 148, one end of which is joined to the oarlock connector 152,and the other end of which is joined by means of connector structure150, which as shown may comprise a flange and an associated pin or othermechanical fastener element for securing the shaft of the shock absorberto the nacelle 110.

The oarlock connector 152 is also connected, on either side of the towerwith yaw-damping shock absorbers. As shown in FIG. 3, a shock absorber153 is generally horizontally disposed, with its stem 154 at one beingjoined to the oarlock connector 152, and with the opposite stem 155being secured to the brace member 132 by any suitable means, as forexample welding, mechanical fastening, or the like. Thus, the oarlockconnector 152 is joined on each side of tower 114 with a correspondingshock absorber, so that the opposite side to that shown in FIG. 3features a shock absorber corresponding to shock absorber 153, wherebyeach side is symmetrically constructed with respect to such yaw-dampingshock absorber.

By this arrangement, said variations in wind speed and/or intensity,e.g., wind gusting and shifts, which tend to displace turbine 101 fromits horizontal axis are damped by pitch-damping shock absorber 148.

Correspondingly, wind shifts which tend to produce displacement of thewind turbine in a horizontal or lateral plane (yaw movement) are dampedby the yaw-damping shock absorbers, including shock absorber 153, and acorresponding shock absorber (not shown) on the opposite side of thetower 114.

It will be recognized that although the coupling arrangement 112 of FIG.3 is illustrated as comprising shock absorbers 148 and 153, that otherpitch-damping and yaw-damping elements may be employed, such as springbiasing elements, or other means which damp such pitch and yawmovements.

Further, while the rotor body 102 of FIGS. 1-3 has been shown withreference to three rotor blades mounted thereon, it will be appreciatedthat a greater or lesser number of rotor blade could be employed.Generally, however, for the sake of relative mechanical simplicity,symmetry, and compactness of structure, from 2 to 6 rotor blades arepreferred.

FIG. 4 shows a cross-sectional view of rotor body 102 of turbine 101 andthe associated power transmission and generator section 135 of theturbine, as contained within nacelle 110.

The rotor body is shown as having rotor blades 104 and 106 mountedthereon.

The rotor body 102 comprises a structural housing including front wallmember 103 and rear wall member 18. At regular intervals about itscircumference, and corresponding to the locations of the rotor blades,are cylindrical wall members 151, defining cylindrical cavities 31 asreceptacles for the appertaining rotor blade stem projections, or bladesspars, 10. The rotor blade stem projection 10 is formed by a cylindricalwall member 19, of smaller diameter than cylindrical wall member 151,which at an intermediate interior portion thereof has a transverselyextending, generally disc-shaped support 22 secured to the wall memberinterior surface, such as by welding, mechanical fastening, etc. Afree-swiveling anti-flyout rod 155 is mounted coaxially with respect tocylindrical wall members 19 and 151 in cavity 31, being secured at itsinner end by mounting block 157, to which a coil spring 21 is secured,by welding, mechanical fastening, etc. The coil spring thus is helicallycircumscribingly disposed about anti-flyout rod 155, and at its upperend abuts the support member 22. Anti-flyout rod 155 extends outwardlythrough a corresponding aperture (not shown) in support member 22 and issecured by means of bolt 11 at its outer extremity to a retainer plate33.

At the outer end of the rotor blade stem projection is disposed a framemember 12, which serves to enclose the cylindrical cavity 31 and also tofunction as a stiffening or rigidifying member for the turbine.

Although not shown for purposes of clarity, bearing means, such asroller or ball bearings may advantageously be disposed betweencylindrical wall members 19 and 151, whereby the former may be rotatedagainst the latter within the limits imposed by the coil spring 21, andthe pitch adjustment subassembly described hereinafter.

In operation, the coil spring 21 acts to radially and torsionally dampthe turbine with respect to shocks and forces exerted on thecorresponding rotor blades. Each of the rotor blade stem projections isconfigured in the above-described manner, such that an independentsuspension system is provided, with each rotor blade being axially andtorsionally damped with respect to radial and torsional forces which mayotherwise damage the turbine or its component parts, or otherwiseadversely affect the efficiency and operability of the turbine assembly.

Also shown in the FIG. 4 embodiment is a variable pitch adjustmentsubassembly disposed in the rotor body 102, and comprising control rod 5and an associated means for adjusting the pitch of the rotor blades to aselected value, in response to axial translation of the control rod.

As shown, the control rod at its distal (downwind) end is joined to aswivel assembly 4, by means of which the swivel can freely rotate on thecontrol rod during rotation of the rotor body. The swivel assembly maybe suitably formed of a wear-resistant material, such as titanium orother high strength, wear-resistant metal or alloy, or other suitabletribological material of construction. The swivel assembly 4 is joinedto a control cable 2 which traverses pulley 3 and is joined at anopposite end to damping element 1, which may be an air-damped shockabsorber, or other damping means such as a spring biasing unit. Thedamping means 1 at its end opposite the connection with cable 2, isjoined to cable 23 which traverses pulley 20 which is secured tomounting block 157 by means of securement pin 161. Pulley 3 is securedby means of yoke element 50 to an anchor element 52 disposed in the aft(downwind) extremity of the rotor body. Symmetrical thereto, the swivelassembly 4 also is joined to control cable 56 traversing pulley 58 andjoined at an opposite end to damping means 54, which at its proximal(upwind) end is joined to cable 163 traversing pulley 165, which ismounted in the same fashion as pulley 20 (specific mounting structurenot shown for clarity). Pulley 58 is joined by yoke member 59 to anchorunit 60.

The control rod 5 at its proximal portion passes through bearing 6 andcollar subassembly 62, and is joined at its proximal extremity to piston66 disposed in hydraulic cylinder 68. The hydraulic cylinder 68 in turnis joined at its respective extremities to hydraulic fluid lines 70 and72, as shown, whereby hydraulic fluid may be selectively introducedthrough either one of hydraulic lines 70 or 72 (with fluidcorrespondingly being removed through the other line of such pair), toeffect translation of the piston 66 in the hydraulic cylinder. For thispurpose the hydraulic fluid lines 70 and 72 may be joined to anysuitable hydraulic fluid pump and reservoir means (not shown forclarity).

By this variable pitch control arrangement, the hydraulic piston 66 maybe selectively translated in a windward or leeward direction tocorrespondingly axially translate the control rod 5, whereby the cables2/23 and 56/163 are selectively "tightened" or "loosened" tocorrespondingly rotate the pulleys 20 and 165, whereby the pitch of therespective rotor blades is correspondingly varied to a desired extent,relative to the pitch at the starting position.

The hydraulic cylinder 68 is circumscribed by a hollow axle 7 mounted inthe interior volume 135 within nacelle 110.

The frontal wall portion 13 circumscribes nacelle 110, and is suitablyprovided on its downwind side with a bearing structure 169, by means ofwhich the frontal wall portion 13 engages the nacelle 110 in a mannerallowing free rotation of the rotor body 102 against the nacelle.

In the interior space 26 of the rotor body, is disposed a shroud 170which is joined to wall 151 at one end, and to frontal wall portion 13at the other. On an interior wall surface of the shroud is mounted aninverse-toothed primary drive gear 171, extending circumferentiallyaround the entire interior surface of the shroud 170, which is ofcylindrical shape. This drive gear engages a reduction gear 8 mounted ona power transmission shaft 9 which is journaled in bearings 172 and 173in transverse wall members 175 and 174, respectively. The powertransmission shaft extends forwardly in the interior volume 135 withinnacelle 110 and is coupled by suitable means to a power generator unit(not shown).

In this manner, rotation of the rotor body 102 during operation of theturbine 101 effects rotation of the shroud 170 bearing drive gear 171 onits interior surface, and drive gear 171 engages reduction gear 8 todrive power transmission shaft 9 and thereby provide motive movement tothe generator unit to produce energy.

The generator unit employed in conjunction with wind turbine 101 may besuitably mounted in the interior volume 135 defined by nacelle 110, ashereinafter described. The generator may be of any suitable type, toproduce alternating current output, or alternatively such generator maybe employed in conjunction with invertor means to provide a directcurrent whereby the energy may subsequently be stored in batteries, orotherwise. Alternatively, both AC and DC power generating means may beemployed, as necessary or desirable in a given end use application.Further, the number of generator units may be increased to any suitablenumber, as hereinafter more fully described, and each of such pluralgenerator units may be suitably coupled to the drive gear, by suitablegearing or motive transmission means as may be usefully employed forsuch purpose and as are well known to those skilled in the art.

In lieu of the above-described gearing system employing a ring gear,(primary drive gear 171), there may alternatively be employed aplanetary gearing system comprising a sun gear which is mounted on acentral shaft or other rotating portion of the rotor body, as well as another suitable gearing or power transmission arrangement, whereby therotational power generated by the rotor body is transferred to the powergenerating means employed in the turbine body.

FIG. 5 is a plan view, in partial section, of a wind turbine assembly200 according to another embodiment of the present invention. Suchassembly comprises a rotor body 202 coupled with and rotatable againststationary nacelle 204 defining an interior nacelle volume includinggenerator, power transmission, and hydraulic control means, ashereinafter described.

The rotor body 202 as shown has mounted thereon rotor blades 206 and208, each of which terminates in a blade stem projection 210 extendingradially inwardly of the rotor body 202. Each of the rotor blade stemprojections 210 may be interiorly assembled and arranged as previouslydescribed with respect to the embodiment of FIG. 4, including theprovision of a coil spring 212 joined at its respective extremities to atransverse support member 214 and mounting block 216 as illustrativelyshown in FIG. 5. The coil spring 212 thus provides independentsuspension for the blade assembly comprising blade 208 and itsassociated blade stem, it being understood that all other bladeassemblies of the turbine system are similarly constructed. It will beunderstood that in lieu of the coil spring assemblies provided in therespective blade stem units, other suspension means may be employed forindependent damping of shocks, radial, translational, and torsionalforces, in place of the specific coil spring subassembly illustrativelyshown in the drawing.

The mounting block 216 is joined to shaft 280 extending through bearings282 and 284 inside the cylindrical housing 286 within the blade stemprojection. The shaft 280 is connected, as shown, to the eccentric campulley 244, by means of which the pitch of blade 208 can be adjusted, bythe pitch adjustment means hereinafter described. Each of the blade stemprojections may be similarly constructed, whereby a predetermined pitchangle may be established for the rotor blades of the wind turbine, priorto and/or during operation.

In the interior volume of the rotor body 202 is mounted a rotor bladepitch adjustment subassembly, including control rod 218 joined at adistal end thereof to swivel assembly 232 and joined at its proximal endto piston 224 in hydraulic cylinder 226 in fluid flow communication withhydraulic feed/discharge lines 228 and 230. The control rod 218 extendsthrough a bearing 222 and is secured to the bearing by a mechanicalcoupling 220 which allows axial movement of control rod 218 through thebearing.

A control cable 234 extends through an eyelet of swivel assembly 232,and traverses pulleys 238 and 240, being connected at its respected endsto pulley 242 and pulley 244, as shown.

By this arrangement, the control rod 218 can be selectively axiallytranslated to vary the pitch of the rotor blades 206 and 208 by rotationof the corresponding blade stem projections 210.

In lieu of the hydraulically-controlled pitch adjustment subassemblyillustratively shown in FIG. 5, there may be employed a mechanical pitchadjustment subassembly, such as a rack and pinion unit with anassociated drive motor. In such mechanical subassembly, a rack could bemounted for linear reciprocating movement in a suitable bearingstructure, with one end of the rack being connected to the control cable234, and with such rack being engaged with a pinion, or alternatively aworm gear, connected in turn to a selectively actuatable drive motor,whereby the rack is able to be forwardly or rearwardly translated totensionally or detensionally adjust the pitch via the control cable.Alternatively, such a rack and pinion arrangement may be directlymechanically coupled to pulleys 242 and 244, without any control cablebeing required.

It will be appreciated that all of the pitch-adjustment and independentsuspension means, as well as all other controllable elements of the windturbine of the present invention may be separately or interdependentlycontrolled by automatic control means, whereby optimal efficiency of thewind turbine may be achieved in its operation. For example, theaforementioned controllable means may be under the concurrent control ofa microprocessor-based control system which is dependently coupled towind speed and/or wind direction sensors, whereby the pitch of the rotorblades and the "springiness" of the independent suspension system may beadjusted automatically to achieve such optimal operation.

At the windward extremity of the rotor body 202, on an inner surface ofthe housing wall is mounted an inverse-toothed primary drive gear 246extending circumferentially around the entire circumferential extent ofthe cylindrical wall. The primary drive gear 246 at its inner surfaceengages reduction gear 251 which in turn is joined to power transmissionshaft 248 journaled in bearing 260 at transverse wall 258. A drive gear250 is mounted at the proximal extremity of shaft 248 and engages gear252 mounted on a shaft (not shown) of generator unit 215. In thismanner, the rotation of the rotor body is transmitted by drive gear 246to reduction gear 251 and the motive power is transmitted to generatingunit 215 to generate power. The power generated by unit 215 may bepassed by suitable power transmission means, e.g. cables or wires, to asuitable power transmission system such as an electric power grid, bymeans and arrangement well known to those skilled in the art.

As previously discussed, the number of generating units in the interiorvolume defined by the nacelle may be one, or more than one. Typically,from 2 to 8 generator units are employed when multiple generators areutilized. Each of such multiple generator units (not shown) may besuitably coupled with the primary drive gear, as hereinafter more fullydescribed, to realize the benefit of such additional power generatingcapacity. In this manner, generating capacities of as large as 750kilowatts or one megawatt can be achieved, with corresponding sizing ofthe wind turbine assembly. The turbine assembly of the present inventionthus may be greatly varied in size and construction thereof with respectto the number, size, and location of generator unit(s) therein.

FIG. 6 shows a front elevation view, looking in the downwind direction,and FIG. 7 is a corresponding side elevation view, of a wind turbineassembly according to another embodiment of the present invention, andfeaturing a self-guying tower construction.

As shown in FIGS. 6 and 7, the wind turbine assembly 300 comprises aturbine 302 mounted on a self-guyed tower 304. The turbine 302 comprisesa rotor body 319 which is coupled with and rotatable against a nacelle306. The rotor body 319 has three rotor blades 308, 310, and 312 mountedthereon, in the previously described manner whereby independentsuspension of each of such rotor blades is provided. The nacelle 306 isjoined to the tower 304 by means of a coupling arrangement 330 which ismore fully shown in the enlarged side elevation view of FIG. 8. Thetower 304 comprises a main tubular member 322 extending through apivotable sleeve 336 which is secured by flange connector 337 to tubularmember 324 which is telescopically mounted on shaft 326 for rotationthereon. The shaft 326 descends downwardly through a footing member 328disposed at ground level G, and extends into the earth for a selecteddistance imparting structural rigidity and integrity to the wind turbineassembly.

Extending transversely outwardly from sleeve 336 and pivotally securedby flange connector 337 to form a conjoint structure therewith, thestrut 332 is secured to sleeve 336 by means of guying cables 338 and340, as shown.

An upwind guying cable 334 is secured at an upper end of the tower andextends over the transverse strut 332 and downwardly over the lower endof main tubular member 322 to a lower extremity which is secured totubular member 324 by means of mechanical fastener 342.

A downwind guying cable 344 is tensionally secured to the upper end oftower 304 and the tubular member 324, being secured at its lower end toa flange extension 346 extending radially outwardly from tubular member324, with the guying cable 344 being joined thereto by mechanicalfastener 348.

By this arrangement, the tower 304 is self-guying in character, and ofextremely light weight and aerodynamic character (the apparent surfacethereof is presented to the wind (see FIG. 6) being very low inmagnitude. This tower arrangement thus is able to respond quickly andefficiently to sudden changes in wind direction and to follow the winddirection in a closely conforming manner.

Referring to FIG. 8, there is shown an enlarged view of the couplingarrangement 330 of FIG. 7.

As shown, the nacelle is coupled with an upper end of the tower 304 by aY-shaped yoke member 350, the upper legs 352 of which (the rear leg notbeing visible in this view) are secured to the nacelle 306 by means ofmechanical fasteners 354. The nacelle 306 is coupled with apitch-damping means 356, as for example a Macpherson strut or othershock absorber or damping means, with the pitch-damping means beingjoined at one end to the yoke member 350 and extending into the interiorspace of the nacelle where such means may be secured to the interiorstructure of the turbine body, such as a bulkhead, partition, or otherstructural member. The stem 360 of the Y-shaped yoke member 350 isdisposed in a cylindrical sleeve 358 extending between end plates 362and 363 of the tower. In this manner, the Y-shaped yoke member 350 isrotatable in sleeve 358. The stem 360 may be yaw-damped inside sleeve358 in any suitable manner, for additional flexibility in changing windconditions. The end plates 362 and 363 are also secured to main tubularmember 322 by any suitable joining method, e.g., welding, etc., asshown. Extending radially outwardly from main tubular member 362 is aflange extension 364 having ring fastener 370 attached engaging ringclip 372 mounted at the extremity of upwind guying cable 334.

Extending downwardly from end plate 363 is an extension flange 365having ring fastener 366 secured thereto and engaging connecting ring368 attached to downwind guying cable 344.

By this arrangement, pitch of the turbine 302 is damped, to an extentdetermined by the tension provided by guying cables 334 and 344. Thiswind turbine assembly may not require any yaw-damping means, since it isof extremely low weight and is a highly efficient free yaw structure,responding efficiently to changes in wind direction. Nonetheless, ifdesired, the yaw of the wind turbine could be damped by suitableyaw-damping means, such as those illustratively described hereinabove inconnection with the embodiment of FIGS. 1-3 hereof.

FIG. 9 is a front elevation view, looking in the downward direction atthe portion of the wind turbine assembly shown in side elevation view inFIG. 8. As shown in FIG. 9, the rotor blades 308, 310, and 312 aremounted on the turbine body at 120° intervals about its circumference,and the nacelle 306 of the turbine is joined to the tower comprisingmain tubular member 322 by a coupling arrangement 330 which in turn isjoined to upwind guying cable 334.

Shown in dotted line representation within the wind turbine aregenerator units 380 and 382, which may be driven by a primary drive gearin a counter-rotational manner, as hereinafter more fully described.

FIG. 10 is a schematic representation of a turbine 400 in which theprimary drive gear 422, which may be associated with the rotor body ofthe turbine, is in engagement with secondary gears 418 and 420 mountedon armatures 410 and 416 of generator units 402 and 406, respectively.This turbine arrangement includes two pairs of coupled generators,generator units 402, 404, 406, and 408 shown in dotted linerepresentation, with units 402 and 408, and units 404 and 406, in pairedrelationship. Hollow axle 424 is shown for purposes of orientation inFIG. 10.

The arrangement shown in FIG. 10 is a schematic representation at adownwind cross-section of the turbine body. A corresponding upwindcross-section adjacent thereto is shown in FIG. 11, in theaforementioned pair arrangement, with the turbines 402 and 408 beingprovided with complementary meshing gearing (not shown) whereby rotationof generator 402 in the direction of rotation indicated by arrow Aeffects counter rotation of generator unit 408 in the directionindicated by arrow B. In like manner, generator units 404 and 406 arepaired and provided with meshing complementary gearing, such thatrotation of generator unit 406 in the direction of rotation indicated byarrow D effects rotation of generator 404 in the direction indicated byarrow C. It will be recognized that a wide variety of arrangements arepossible with respect to number of generator units, gearingarrangements, and innercoupling of generators with one another.

It will be understood that the generator units shown in FIG. 11 may becoupled with one another in any suitable manner, and with any suitablegearing/mechanical coupling for co-rotational or counter-rotationaloperation relative to one another.

FIG. 12 is a schematic representation of a gearing arrangement forside-by-side counter-rotating generator units 502 and 510. Thesegenerators are arranged, with a ring gear 500 being positioned inmeshing contact with driven gears 506 and 516. Driven gear 506 meshinglyengages a secondary gear 504 attached to the extended armature ofgenerator 502. Generator 502 may be provided on its armature with afurther gear engaging counter rotation gear 508, which in turn ismeshingly coupled with a gear secured to the armature of generator 510.

Driven gear 516 meshingly engages ring gear 500, as well as secondary514. Secondary gear 514 in turn meshingly engages armature gear 512 ofgenerator unit 510.

The different gearing shown for generator units 502 and 510 are shown asillustrating different constituent gearing arrangement which may beadapted for transferring motive power from the rotor body of a turbineby means of a ring gear to driven and secondary gears. This differencebetween the gearing arrangements of the respective turbines in FIG. 12is shown for illustrative purposes only, it being recognized that intypical practice, the gearing arrangements for each of the generatorunits will be constructed and arranged consistent with the rotationalspeeds appropriate to the component generator units.

FIG. 13 shows a gearing arrangement for turbines in which fourequal-size gears 522, 526, and 528 are disposed in sequential meshingrelationship to one another as shown, within nacelle 520. In thisarrangement, in which the gears are arranged around central axle 530,gears 522 and 526 rotate in a first direction of rotation, while gears524 and 528 rotate in an opposite direction of rotation.

FIG. 14 shows a gearing arrangement in which generator units 536 and 538are positioned within nacelle 534. Generator unit 536 is provided witharmature gear 542 which is in meshing engagement with transmission gear548 joined to shaft 546, at the opposite end of which is providedtransmission gear 550 in meshing engagement with armature gear 544 ofgenerator unit 538. There is thus provided a counter-rotation gearingarrangement by direct 90 axle linkage forward of the generators, whichare arranged symmetrically with respect to the central axle 540.

FIG. 15 is a schematic representation of a turbine arrangement whereingenerator units 562, 564, 566, and 568 are arranged symmetrically withrespect to central axle 570, within nacelle 560. In this arrangement,each of the generator units is provided with a complementary gearingarrangement, whereby diagonally opposite generators units, e.g.,generators 560 and 566, rotate in a first direction of rotation, whilethe other diagonally related pair of generator units 564 and 568 rotatein an opposite direction of rotation to the first pair.

It will therefore be appreciated that a number of specific spatialarrangements are possible for a multiplicity of generator units, asnecessary or desired for a given wind turbine assembly, and that thespecific gearing arrangement for transferring motive power of the rotorbody to the generator units may be correspondingly varied, to effect anydesired rotation scheme (co-rotation, counter-rotation, or a mix of bothmodes), with respect to constituent generator units.

While the invention has been described herein with specific reference todownwind configurations of wind turbine assemblies, it will beappreciated that the invention is not thus limited, but is usefullyemployed in upwind as well as downwind systems.

It will be recognized that the specific pitch adjustment system of theinvention may be widely varied, as regards its constituent components.For example, referring again to FIG. 5, the adjustment pulleys 242 and244 may be of cam or other noncircular shape, to provide a "neutral"position of adjustment.

Further, the tower employed with the wind turbine of the presentinvention may be widely varied in structure and operation. For example,it may be desirable in some instances to employ a pivoting booming towercapable of 360° damped yaw operation, which is provided with a redundantlimited yaw damping system mounted at the upper end of the tower, withsuch redundant system being of a type as employed in the illustrativeembodiment of FIG. 3. The tower may be constructed to accommodatelimited yaw damping outside of a zone of free yaw operation, which maybe of any desired angular extent, e.g., 270°, outside of which thedamping means would effect damping retardation of the yaw movement. Inan upwind configuration, the tower is preferably of a driven yawcharacter, with solid yaw damping at the upper end of the tower inconnection with the coupling of the tower to the nacelle of the windturbine.

It will be further recognized that the specific arrangement of thehydraulics in the illustrative embodiments herein described may bevaried, to place such hydraulics in the proximal end of the nacelle, andwith the control rod intermediate the rotor body and the nacelle beingcoupled with a mono-shock or other suitable damping means to provideadditional damping capability to the turbine.

Accordingly, while the invention has been described with respect tospecific features and embodiments, it will be appreciated that numerousvariations, modifications, and embodiments are possible, and all suchvariations, modifications, and embodiments are therefore to be regarded,as being within the spirit and scope of the invention.

What is claimed is:
 1. A wind turbine assembly including a rotor bodyhaving mounted thereon a plurality of rotor blades, wherein each of therotor blades is joined at an inner extremity thereof to a blade stemprojection extending interiorly into the rotor body and securedtherewithin to the rotor body by torsional- and axial-shock dampingconnection means, wherein each blade stem projection comprises a hollowcylindrical housing defining a central longitudinal axis therein, with asupport member interiorly disposed in the housing at an intermediateposition along its axis and fixedly secured to the housing, a shaftfixedly secured at one end thereof to the rotor body and coupled at itsother end with the support member in a manner allowing limited axial androtational movement of the housing relative to the rotor body, and alongitudinally outwardly biasing means between the support member andthe rotor body, extending along the axis of the housing and outwardlyabuttingly biased against the support member, whereby the biasing meansprovides torsional and axial shock damping to the rotor blade.
 2. A windturbine according to claim 1, wherein the tortional- and axial-shockdamping connection means comprise a helical coil spring as a shockdamping element and said biasing means.
 3. A wind turbine assemblyaccording to claim 1, wherein each of the rotor blades is secured to therotor body by independent torsional- and axial-damping connection means,to provide independent suspension to each of the rotor blades.
 4. A windturbine assembly according to claim 1, comprising from 2 to 6 rotorblades.
 5. A wind turbine assembly according to claim 1, comprising from2 to 8 power generator units coupled in power generating relationship tothe rotor body.
 6. A wind turbine assembly according to claim 1, whereinthe rotor body is coupled to a nacelle for rotation with respect to thenacelle, wherein the rotor body comprises a circumferentially extendingring gear gearingly engaging a generator mounted in said nacelle.
 7. Awind turbine assembly according to claim 1, wherein the rotor body iscoupled to a nacelle for rotation with respect to the nacelle, andfurther comprising a self-guying tower to which the nacelle is secured,wherein the self-guying tower comprises: a shaft securable to a supportstructure; a tubular support member telescopically mounted on the shaftfor rotation thereon; a flange connector mounted on the tubular supportmember at an upper end thereof; a sleeve pivotally mounted on the flangeconnector; a main tubular member extending through the sleeve and havinga lower end and an upper end; nacelle mounting means joined to the upperend of the main tubular member and connected to the nacelle; atransverse strut extending transversely outwardly from the sleeve andsecured to the sleeve to form a conjoint structure therewith; a firstguying cable secured at a first end thereof to the nacelle mountingmeans at the upper end of the main tubular member, extending downwardlyover the tranvsverse strut and the lower end of the main tubular memberand secured at a second end thereof to the tubular support member; and asecond guying cable secured at a first end thereof to the nacellemounting means at the upper end of the main tubular member and securedat a second end thereof to the tubular support member.
 8. A wind turbineassembly according to claim 7, wherein the nacelle mounting meanscomprise:a cylindrical sleeve secured to the upper end of the maintubular member; a shaped yoke swivel mounting member comprising upperlegs joined to the nacelle at opposite sides thereof by mechanicalfastening means, and a lower stem telescopically positioned in thecylindrical sleeve, to permit rotation of the nacelle and rotor bodyrelative to the tower; and a pitch biasing and damping memberinterconecting the nacelle and the yoke swivel mounting member.
 9. Awind turbine assembly including a rotor body having mounted thereon aplurality of rotor blades, wherein each of the rotor blades is joined atan inner extremity thereof to a cylindrical blade stem projectionextending interiorly into a cylindrical receiving cavity in the therotor body and secured therewithin to the rotor body in a mannerallowing limited rotation of the blade stem projection relative to therotor body, said limited rotation corresponding to a selected range ofpitch of the associated rotor blade, and means for selectively rotatingthe cylindrical blade stem projections of each of said rotor blades bycorresponding degrees of rotation to provide a predetermined pitch ofsaid rotor blades, including torsional and axial biasing and dampingmeans mounted within the cylindrical blade stem projection andconnection means interconnecting the biasing and damping means in thecylindrical blade stem projection with the rotor body, said biasing anddamping means serving to maintain the cylindrical blade stem projectionin a torsionally and axially biased base position, a longitudinallyextending control rod mounted coaxially within the rotor body for axialmovement in either of opposing axial directions, means for selectivelyaxially translating the control rod in a desired one of said opposingaxial directions, and cabling coupling the control rod and saidconnection means so that axial movement of the control rod to a selectedextent by said translating means in a first one of said opposing axialdirections causes the cabling to be tensioned to tensionally rotate theconnection means and cylindrical blade stem projection connectedtherewith so that the rotor blade associated with said rotatedcylindrical blade stem is adjusted to a selected pitch level, and axialmovement of the control rod to a selected extent by said translatingmeans in a second one of said opposing axial directions causes thecabling to be detensioned to detensionally rotate the connection meansand cylindrical blade stem projection connected therewith in an oppositedirection of rotation toward said base position so that the rotor bladeassociated with said rotated cylindrical blade stem is adjusted to otherselected pitches.
 10. A wind turbine assembly according to claim 9,wherein the means for selectively axially translating the control rod ina desired one of said opposing axial directions comprise a piston joinedto the control rod and mounted in a hydraulic cylinder, with means forselectively introducing hydraulic fluid into the cylinder to effectaxial translation of the control rod in a desired one of said opposingaxial directions.
 11. A wind turbine assembly according to claim 9,wherein the cabling is part of a cable and pulley arrangement.
 12. Awind turbine assembly according to claim 1, wherein the cable and pulleyarrangement includes a fluid-damped shock absorber coupled to the cable.13. A wind turbine assembly including a rotor body having mountedthereon a plurality of rotor blades, a nacelle to which the rotor bodyis coupled for rotation with respect to the nacelle, and a tower havingan upper portion to which the nacelle is secured by coupling means, anda lower portion positionable on a support body, the tower upper portionincluding a cylindrical member at an upper end of the tower, wherein thecoupling means comprise: a swivel mounting member comprising upper legsjoined to the nacelle at opposite sides thereof by mechanical fasteningmeans, and a lower stem telescopically positioned in the cylindricalmember at the upper end of the tower and extending downwardly from thecylindrical member to a bottom stem portion, to permit rotation of thenacelle and rotor body relative to the tower; an oarlock connectorjoined to the bottom stem portion; a pitch biasing and damping memberinterconecting the nacelle and the oarlock connector, for pitch dampingof the nacelle; and yaw biasing and damping means connecting the oarlockand upper portion of the tower, whereby the pitch damping/biasing memberand the yaw biasing and damping means bias the rotor body and nacelle toa selected base position in relation to the tower, and dampen pitch andyaw displacements from said base position.
 14. A wind turbine assemblyaccording to claim 13, wherein the pitch biasing and damping member andthe yaw biasing and damping means are independently selected from thegroup consisting of spring biasing elements, tensionally flexible guyingcables, and fluid-damped shock absorbers.
 15. A wind turbine assemblyaccording to claim 13, wherein the tower lower portion is adapted forground surface mounting of the tower.